Modern gas turbine aircraft engines have a gearbox that is mounted on their external cases. The gearbox is generally positioned under the engine case and uses power from the engine to drive the major accessories needed for engine functions, such as generators for electricity, pumps for circulating fluids and heat exchangers for cooling oil or heating fuel. The accessories are frequently mounted on the gearbox.
Various mounting arrangements are used to mount the gearbox to the external case of the engine. The gearbox is often connected to the engine case at two or more locations along the length of the gearbox. For example, a forward V-shaped link may be used to fasten the front of the gearbox to the engine. A plurality of side hanger links may be used on either side of the gearbox housing to stabilize the gearbox. Further, a locator or positioning device may also be used to provide alignment of the gearbox with respect to the engine case and prevent undesirable movement of the gearbox relative to the engine.
It is known to decouple the gearbox from the engine to protect both from extreme loads by allowing some floating of the gearbox. It is also known to provide fuse systems with dampers or a locator with shearing diaphragms to decouple the gearbox from the engine case to protect form extreme loads.
There is, however, a need to provide a gearbox positioning device which is capable of relieving thermal growth from the engine case and/or support linkage imbalance.